Stiff Collar Tip Conclusions

Stiff Collar Conclusions

When using solely pool noodle foam, it is clear that using the large leather disk construction rather than the small disk has significantly superior durability over the traditional pool noodle construction.

Using a stiff foam collar is clearly superior in durabiltity compared to the pool noodle only construction, no matter what other combinations of components are chosen.

Using a stiff foam collar, with the large leather disk, with friction tape, is clearly the best construction with surprisingly little evidence of degradation of the foam. In fact, before I ran this test, I didn't think it was possible to fire bolts with pool noodle foam in the tip and achieve virtually no destruction of the foam.

My constructions seem to indicate a little trouble aligning the stiff collar correctly when forcing them over the friction tape. The solution is either to enlarge the hole in the collar, or remove the friction tape. I tried the latter and achieved satisfactory results. It seems that a litle bit of stickiness will help with durability. I'm considering trying to use rubber cement to help hold the collar onto the pipe instead of the friction tape. This would readily allow construction and adjustment until the rubber cement is solid. The rubber cement is flexible which is very important for this application, plus it should be easy to clean up off of the pipe when renovating bolts.

I have been encountering 2 problems with the existing pool noodle tips:

When hitting targets solidly, they degrade fairly quickly, resulting in softness when squeezing the sides.

After use, they quickly start having trouble keeping the tips aligned well on the end of the pipe. They don't flop over enough to fail, but enough to affect accuracy.

Using a large leather disk, the durability is longer, but the tip still gets a little wobbly because of a lack of support of the tip. Using the stiff collar foam, the tips stay aligned on the pipe and last significantly longer, longer than even the pool noodle collared tips with the large leather disk.

The extra cost of the tip is easily outweighed by the longer lasting pool noodles, and on top of that, it is clear that the collar itself can be reused, even after degradation of the pool noodle. For example, after P2 was fired 30 times, I reused the collar and built P5 and shot it another 20 times for the 45 degree angle test. It still shows no sign of degradation of the collar.

I have not yet built a bolt with black siloflex, but the weights I've seen so far would seem to probably put the black siloflex bolt with a stiff collar at 15.5 to 16 ounces. Cutting off 3" would seem to be required when using black pipe to keep the weight well below 16 ounces. Of course, cutting 3" off of the yellow would improve the weight issue with the yellow also. Making these with the 1/2 tennis ball option is probably not achievable.

There are no impact measurement mechanisms currently so impact damage is only conjecture. One can assume however, that the impact would be marginally higher with these tips as the pool noodle remains completely intact, leading to lower stop distances of the pipe. With traditional construction, the pool noodle quickly begins to degrade, resulting in marginally longer stopping distances as the pipe projects into the pool noodle. With the stiff collar tip, there is clearly no such projection into the foam so the pipe must stop in a shorter distance. Also, some of the force of impact is absorbed in the destruction of the pool noodle tips. Clearly, there is less destruction per hit, resulting in slightly higher impact. This is all pure conjecture and quite arguable. The only observable behavior was that all the shots tended to have a lively bounceback. I don't know what this indicates.

Safety should not be an issue as the stiff foam even has a little bit of give to it. Also, the stiffer foam is not used in the striking tip. Indeed, it should result in less incidents as the collar holds tips in place better, and cause the pool noodle foam to last substantially longer, with no apparent chance whatsoever for the end of the pipe to come into contact with the fighter. The only contact with a fighter would be a case where the bolt turns sideways in flight and hits the fighter sideways. This can happen due to a misfire, poor fins, or deflection. The sideways contact with the stiff foam should not be any worse than contact with the hard plastic tube.

It is clear that we should proceed to approving this construction for use in combat siege.

A comment on the compression measuring device. This is a somewhat crude device which was never intended to be all that accurate. Some may notice an anomaly with the measurements for tips P2-P4 between 15 shots and 20 shots. I had to take a break after making the 15 shot measurements for about a week or so. When setting back up, it was a bit colder so I set up the measurement device inside where it was warmer. The device uses a cheap bathroom scale which probably is not all that accurate. Rather than attempt to compensate somehow, I just recorded what I saw. So I guess we should assume about a +/- 5 pound error when comparing measurements.

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